Who is responsible for knowing the soil under a new pool, and what should happen when nobody orders a report?
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Nearly every residential pool contract in Arizona assigns subsurface investigation to the owner. That is standard and it is legitimate. Very few owners act on it, usually because nobody explained what it was for. Absent a geotechnical report, no builder knows the soil with certainty, and that includes us.
This is the single largest unpriced risk on a residential pool in Southern Arizona, and it is almost always transferred to the person least equipped to evaluate it.
WHAT THE CONTRACT USUALLY SAYS. The structure is consistent across the industry: the builder discloses that subsurface conditions are unknown, and responsibility for obtaining a geotechnical investigation sits with the owner. That is a normal and defensible allocation. It is also one that most owners sign without registering, because the clause reads as boilerplate and nothing in the sales process explains what it is for.
WHAT A GEOTECHNICAL REPORT COSTS AND WHAT IT BUYS. Generally the low thousands to low five figures depending on scope. What it buys is the removal of a variable that otherwise gets resolved during excavation, at a point where every option is more expensive than it would have been in design.
ONE REGIONAL CONDITION WORTH KNOWING. Areas of Marana carry roughly 20 feet of clay and organic soils in varying layers. Expansive fat clay is also a larger build risk in Cochise County than any barrier rule on the books. Neither of those is a substitute for site data; they are reasons to get site data.
WHAT WE RECOMMEND ANY BUILDER DO WHEN AN OWNER DECLINES A REPORT. Do not quietly default to the minimum. Assemble the available evidence and make a documented determination from it. Sources that exist and are usable: a custom soils map maintained by a shotcrete and steel installer working the region, floodplain data, University of California Davis soil survey data, and Pima County and Pinal County reports. Then walk the owner through four things and write down that you did: what is known, what is not known, what a geotechnical report would resolve, and how the design intends to handle the uncertainty.
That is what we aim to do and what we would recommend to anyone in this trade. It is also the thing a homeowner can ask any builder for by name, which is the reason it is published here rather than kept internal.
NONE OF THIS REPLACES THE REPORT. It is a method for reducing exposure when the owner declines one. An owner who can afford the investigation should order it, and the honest version of this advice is that the money is better spent there than on almost any finish upgrade of the same value.
Scope of this record. These are Omni Pool Builders & Design’s typical standards and what we would typically recommend. They are not a code requirement, not a representation about any particular project, and not a substitute for the sealed engineering and the geotechnical investigation for the site in front of you. Where a project’s sealed engineering says something different, the sealed engineering governs.
Important. A typical recommendation, not a code requirement and not a representation about any specific project. Describes the industry contract structure neutrally and makes no claim about any builder’s intent.
Authority: Omni Pool Builders & Design typical recommendation. Industry-standard contract allocation of subsurface investigation to the owner.. Verified 2026-09-13. Evidence grade: RECOMMENDED.
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